04 May 2018Joel Vega

Continued and higher use of anticholinergic (AC) drugs among the elderly was linked to dementia risk, according to a new UK study. AC drugs are often prescribed to elderly patients with overactive bladder (OAB) or incontinence complaints.

“The recent publication of the paper “Anticholinergic drugs and risk of dementia: case control study” identified an association between exposure to drugs with anticholinergic properties and incident dementia diagnosis,” wrote Dr Adrian Wagg in a commentary sent to the European Association of Urology (EAU).

Wagg referred to the paper published recently by the peer-reviewed British Medical Journal (BMJ). The study was led by K. Richardson, et al. (BMJ, 2018. 361: p. k1315).

The study, considered the largest of its kind to date, has prompted the researchers to say that clinicians should avoid long-term prescription of some anticholinergics to patients aged 45 and over.

The study used the Anticholinergic Cognitive Burden (ACB) scale, which was developed by consensus and literature review. Wagg noted that serum anticholinergic activity, however, has been found to have no link with cognitive impairment in randomised studies [1].

“There are approximately 16 published scales and measures to measure anticholinergic burden, all with variable inclusion and classification of drugs with anticholinergic properties. No score has been truly validated in terms of anticholinergic activity, and there is significant variation between them,” wrote Wagg.

Wagg further noted that “there were in addition, inconsistent associations between ACB scale and class of medication.”

“For example, antipsychotic drugs with a score of 3 showed no association whereas antidepressant and urological agents with the same classification did show such an association. Both oxybutynin and tolterodine were identified as culprit urological agents in this study,” Wagg said, adding that oxybutynin’s immediate release has been consistently associated with cognitive impairment in older people in short-term studies.

He added that tolterodine has been “…associated with short-term reversible cognitive impairment [2], but also associated with no observable change in cognition in a controlled trial [3].”

According to Wagg, evidence already suggests that community-dwelling and institutionalised older people with OAB have more co-morbid conditions and are likely to have more impairments in activities of daily living than those without OAB [4].

He further commented: “The recording of well-established risk factors for cardiovascular diseases such as obesity and smoking were poorly recorded in this study. Overactive bladder (OAB) and urgency incontinence in older people shares classical cerebrovascular and cardiovascular risk factors with dementia, whether it is likely that the development of OAB and urgency incontinence is a presage of dementia up to 20 years later is a question worthy of further investigation. “

Wagg said the take-home message from the BMJ paper “… is that estimated cumulative high levels of anticholinergic burden (as measured by the ACB scale score) may be a minor risk factor for future cognitive impairment,” and added that the benefit of successful treatment of OAB in older persons is “unquestionable” [5].